Conventionally, there has been disclosed a map retrieving device that can express a map in three dimensions by processing with a small calculation load. This map retrieving device reads out map data of area near the current position of a vehicle calculated by a position calculating device, or map data of the map to be displayed in a range specified with an input device, from a map storage device. Subsequently, a processing unit carries out transparent transformation of four peaks of the read map data based on a view point and fixation point coordinates input from the input device, maps the map data on the transformed coordinates, and clips the data, to display the map after mapping in an output device (see Patent Document 1 below).
Patent Document 1: Japanese Patent Laid-Open Publication No. H09-138136